Vaporproof lighting unit



Dec. 16, 1930. 1 A VOLK v 1,785,538

VAPORPROOF LIGHTING lUNI T Filed April 4, 1929 INVENTOR .wf/@#4 m4 ff.

ATTORN EY Patented Dec. 16, v1930 UNITED vSTATES JOSEPII A. VCDL'KOE NORWALK, CONNECTICUT VAPORPROOF LIGHTING' UNIT Application filed April 4,

The present invention relates to vapor proof lighting units and is more particulan ly directed toward the provision of improved mounting devices for securing glass globes to their supports.

Lighting units of the type generally designated as vapor proof are seldom suficiently tight to prevent the leakage of vapors and gases into the unit through the joint between the glass part and its support. The usual construction employed for this purpose comprises a support having an internally threaded part adapted to receive the threaded neck of a glass globe. The .globe is threaded as tightly as possible against a gasket, but this simple construction has been found to be defective in providing a gas tight joint.

The pitch of the threads on the glass is necessarily rathersteep (approximately four threads per inch). The threads cannot be made accurately to size and hence do not closely lit the threads on the support. The friction between these parts is high, and only v a small turning effort may be employed as it must be transmitted through the glass. Ow-

ing to the alternate heating and cooling of the unit when the lamp is burned and Vextinguished, considerable pressure differences develop between-the enclosed gases and the outside atmosphere.

extent that the enclosed gas `may become vapor laden to a dangerous degree.

proved form of fixture construction whereby the glass envelope is so securely held that the,

breathing of the unit through the gasket is effectively prevented.

According to the preferred form of con-lv about without applying force to turn theV globe. i j The accompanying drawings show, for

purposes of illustrating the present inven' On account of this pres-V sure diiierence, the unit breathes to such an,

1929. senal 110.352,36?.

tion, two of the many possible embodiments in which it may take form, it being understood that the drawings are illustrative -of the invention rather than limiting the same.

i In these drawings:`

Figure 1 is an elevational view of a vapor 'proof unit, with parts'in section;

Figure 2 is a plan view; and

Figure 3 is a perspective view of a form of construction.

Vapor proof lighting units of the type conmodified templated by the present invention are' generally connected to a conduit system through which the supply wires are brought. One of the pipes of such a system is indicated at 10. A downwardly flaring supporting number 11,

. generally in the form of a casting, is threaded at l2 to fit the pipe. It may, if desired, be shaped to receive a wrench so as to facilitate tightening it in place. y ,j j The lower part of the support 11 is threaded as indicated at 13 and is provided with gear teeth 14. It has a bottom flange or partition plate 15 apertured at 16 to receive a keyless socket 17. The socket is flanged as shown atlS and provided with holes 19 to receive screws A2O. The screws pass through holes in a gasket 21 and are threaded into tapped holes22fin the support. The socket has the usual terminals at the upper side to permit connectingit to the'wiring and has socket contacts to'support a lamp bulb 23. The present invention contemplates an im- A ring 24 is threadedonto thesupport, the ring having'a number ofthreads 25at its" upper end for this purpose. The ring also has interiorly disposed gear teeth 26 0pposite the teeth 111 and is interiorly threaded at 27 to receive the threaded neck 28 of a closed glass globe or envelope 29. lThe threads 27 are of higher pitch than the threads V15.

Assuming that the stationary parts of the unit have been secured together, the ring 24 is threaded up onto the support. It is then gripped while the' glass globe is threaded into place to bring the end of the'globe against the gasket. This threading action cannot produce a very tight joint for reasons above 'referred to.

y To tighten the joint, one may employ atool such las indicated at 30. lt'

consists merely of a handle 3l and pinion 32, the latter being adapted to engage both rows of gear teeth. lVhen the pinion is turned in the proper direction, the ring 24 will be turned relative to the support and the glass globe, which cannot turn on account of the friction of the gasket and glass. As the ring turns it tends to thread onto the glass faster than it threads otfthe support, owing to the difference in pitch of the threads, and hence draws the glass more tightly against the gasket. This joint is much tighter than can be obtained by twisting the globe itself. TheV joint is gas tight, and in order to permit the unit to breathe through the conduit system, there may be provided a suitable passage way such as the drilling 33 in the socket body 17.

In the modied form of construction shown in Figure 3, the ring 24a is provided with notches 34 so that one may employ a tool, such as a screwdriver, to tighten the ring. The shank of the tool may be placed in the notch 34 and the end of the tool engaged with the teeth or notches 35 o-n the supporting member 11a.

It is obvious that the invention may be emv bodied in many forms and constructions within the scope of the claims, and I wish it tobe understood that the particular form shown is but one of the many forms. Various modifications and changes being possible, I do not otherwise limit vmyself in any way with respect thereto.

vWhat is claimed is:

l. The combination with a closed glass envelope having a threaded neck, of a ring threaded onto the neck, a support threaded into the ring,and a gasket interposed between the support and neck of the glass envelope, the threads between the'ring and the neck and the support being of different pitch whereby a diiferentlial action isl obtaine'idby turning the ring while the support and envelope are stationary. Y

2. The combination with ak closed glass envelope having a threaded neck, of a ring threaded onto the neck, a support threaded into the ring, and a gasket interposed between the support and neck vof the glass en# velope, the threads between the ring and the neck and the support being of different pitch whereby a differential action is obtained by turning the ring while the support and eneciV velope are stationary, the ring and supporty having a co-operative tool engaging device to facilitate tightening the parts. Y

3. The combination with a closed glass envelope having Va threaded neck, of a ring threaded onto the neck a support threadedY into the ring, and a gasket interposed between the support and neckrof the glass en.

velope, the threadsbetween the ring and the neck and the support being of dierent pitch whereby a-Vdifferential actionris obtained by Vthreaded at its lower end, a ring threaded on to the support and having threads to receive the neck of the envelope, and a gasket interposed between the support and envelope, the threads Von the lower end of the support and on the neck of the envelope being slightly different whereby a differential action is obtained upon turning the ring to securely clamp the envelope in place, there being a gas passage leading to theupper part of the support to ensure breathing of the unit through the conduit system.

5. A vapor proof lighting unit comprising a closed glass envelope having a threaded neck, a hollow support threaded at the upper end for connection to a conduit system, and threaded at its lower end, a ring threaded on tothe supportand having threads to receive the neck of the envelope, a gasket interposed between the support and envelope, and a lamp socket secured to the support and holding the gasket to the support, the threads on the lower end of the support and on the neck of the envelope being slightly dierent whereby a differential action is obtained upon turning the ring tov securely clamp the envelope 1n, place, there being a` gas passage leading tothe upper part of the support to ensure breathing of the unit through the con-V duit system.

6. A vapor proof lighting un'it comprising.

the gasket to the support, the threads on the lower endof the support and on the neck of theenvelope being slightly different whereby a differential actionis obtained upon turning theV ring to securely clamp the envelope in place, the socket being provided with a ventilation hole to ensure breathing of the unit through the conduit system.

7. In combination, a glass envelope having a threaded neck, a support havingl a lower portionof substantially the same diameter aszthe neck and threaded lin the. same direction ata slightly finer pitch, and aring having its lower portion interiorly threaded to it the neck and its. upper portion interiorly threadedto fit the support. Y

8. In combination, a glass envelope having a threaded neck, a support having a, lower portion offsubstantially the same diameter as the neck and threadedin the same direction at a slightly finer pitch, and a ring having its lowerl portion nteriorly threaded to fit the neck and its upper portion interiorly threaded to t the Support, the support hav-v ing a row of gear teeth and the ring having a row of gear teeth opposite these on the ring, said gear teeth being adapted to receive a pinion for the purpose of tightening the glass part in place.

Signed at New York city, in the county of New York and State of New York, this 3rd day of April, 1929. i

JOSEPH A. VOLK. 

